1. Field of the Invention
The present invention relates to the prevention and treatment of bedbug infestations.
2. Description of the Related Art
Bedbugs, known scientifically as Cimex lectularius (Cimicidae), are small wingless insects that feed exclusively on the blood of warm blooded-animals, preferably human blood. Newborns, called hatchlings or nymphs, are tiny, about the size of a poppy seed, while adults grow to about ¼ of an inch long. Their shape is oval and flattened. Over millions of years bedbugs have evolved as nest parasites—inhabiting the nests of birds and the roosts of bats. Some of them have adapted to the human environment and live in the places where humans sleep.
Bedbugs can survive a wide range of temperatures and atmospheric compositions. Below 16.1° C. (61.0° F.), adults enter semi-hibernation and can survive longer. Bedbugs can survive for at least five days at −10° C. (14.0° F.) but will die after 15 minutes of exposure to −32° C. (−26° F.). They show high desiccation tolerance, surviving low humidity and a 35-40° C. range even with loss of one-third of body weight.
Bed bugs crawl, moving about as fast as an ant. They cannot jump or fly. They usually stay in dark, tight hiding spots—like the insides of wall—and come out of the hiding spots only to feed. Once they have fed, they scurry back into their hiding places.
Bedbugs feed only on the blood of warm-blooded animals, preferably humans. Their name is derived from the bedbug's preferred habitat of houses and beds or other areas where people sleep. Bedbugs, though not strictly nocturnal, are mainly active at night and are capable of feeding unnoticed on their hosts.
In the developed world, bedbugs were largely eradicated as pests in the early 1940s. However, they have increased in prevalence in recent years, and have now reached epidemic status in various regions of the United States and the World. This has resulted from a variety of factors, including the banning of pesticides such as DDT, greater foreign travel, more frequent exchange of second-hand furnishings among homes, a greater focus on control of other pests resulting in neglect of bedbug countermeasures, and an increasing resistance of bedbugs to pesticides.
Any place with a high turnover of people spending the night has a particularly high risk of infestation. Such dwelling places include, for example, hotels, hostels, resorts, apartments, barracks, cabins, cruise ships, dormitories, dressing rooms, health clubs, homes, hospitals, motels, motor homes, moving vans, nursing homes and other such places, referred to generally herein as “dwelling places.” Bed bugs don't prefer locations based on sanitation or people's hygiene.
Most bedbugs live near where people sleep, hiding near the bed, a couch or armchair (if people nap there), or even near cribs and playpens. Their flat bodies allow them to hide in cracks and crevices around the room and in furniture joints. Bed bugs can be found alone, but they prefer to congregate together in good hiding spots. Even when they congregate in groups, they are not social insects and don't build nests. Adults can sometimes live up to a year without a meal.
In the pest control field, it has previously been known to use liquid pesticides to kill insects, including bedbugs. For example, it has been known to spray pesticides throughout a dwelling house and onto all of its contents. Sometimes this involves tenting the entire structure and fumigating the entire structure under the tent.
However, it is not always practical to fumigate or otherwise spray pesticides throughout an entire dwelling structure and its contents. For a hotel, this would require emptying all of the guests out of the hotel for an extended period of time. Moreover, if bedbugs are found in a single room, treating that one room using pesticides will often simply drive the bedbugs into the adjacent untreated room, with the bedbugs traveling through the hollow interior walls, where they are protected from the full brunt of the pesticides.
Another disadvantage of spraying or fumigating with liquid pesticides is that, once an infestation has been controlled using liquid pesticides alone, the pesticides rapidly begin to lose their effectiveness. Thus, controlling a current infestation with liquid pesticides might not prevent future infestations.
It has also been known to use foam as a delivery vehicle for pesticides, in applying pesticides inside walls. For example, pesticide foams have been injected into walls to kill termites living inside the walls. However, the pesticide foams that have commonly been used to kill insects inside walls have been relatively thin and unstable, and rapidly run to the bottom of the wall, forming drops or pools of liquid at the bottom of the wall. This has usually provided an advantage, in that many insects, including termites, are attracted to drops or pools of liquid, including the drops or pools of pesticide-laden liquid that rapidly form at the bottom of the inner wall when a typical foam is injected into the wall.
However, such foam insecticides and approaches have been generally ineffective against bedbugs. Bedbugs are not attracted to pools of liquid, and will avoid any pools of pesticide in the void spaces of a wall. Moreover, even if they come into brief contact with a liquid pesticide or a thin foam pesticide, they are protected by their hard exoskeleton and will usually survive the brief contact. Bedbugs are “non-grooming” insects, which means they do not lick substances from their outer surfaces. Thus, they cannot be readily controlled using known foam pesticides.
One widely used method for treating bedbugs focuses on heating the interior of the building and its contents to high temperatures, in the range of 118-130 F, to kill bedbugs inside the dwelling. However, this method of dealing with bedbugs has disadvantages. It uses a great deal of energy and requires expensive, specialized heaters and other equipment. Heat treatment can also cause damage to the interior of the dwelling or to its contents, such as furniture and vinyl fixtures.
Moreover, heat treatment does not prevent future re-infestations of the same space, after a current infestation has been eradicated. The same is true of most other methods of dealing with bedbug infestations, including vacuuming, tenting with pesticides, freezing and other treatment methods. If any bedbugs survive the heat treatment, or if any new bedbugs are brought into the dwelling in the future, a new infestation can develop.
Thus, there is a need for a different method for treating or preventing infestations of bedbugs, which will control any current infestations and will also limit future infestations for an extended period of time, while avoiding the drawbacks and disadvantages of the prior art techniques for controlling bedbugs.